The most important things in risk management are working with errors and minimizing their consequences.
It is more in terms of how to manage risk and not how to evaluate losses based on errors. I think you got something wrong there. Correction of errors are for post-trading evaluation.
You manage risk by doing research on the projects you are investing in and their regular reports to keep track of their growth and development. Investors want a good quarterly report nothing more.
As a rule, errors occur most often due to psychological conditions, in other words, when you are emotionally involved in trading.
Errors cannot be judged like that. It is easy to judge them after committing them but not always possible to change the outcome when the event is actually occurring.
The first thing you should do in the process of your training in trading is to work with your emotional states, because it depends on him how your thinking will work, interruptions and mistakes, or clearly and harmoniously.
If a person is not emotionally well, why would they trade. Of course here comes the question of people who are trying to get rich quick and those who are professionally trading everyday.